The present invention relates to a hoisting device for an elevator that lift up and down a moving cage by moving a main rope connected to the moving cage.
A hoisting device for an elevator is disclosed in JP-A-63-12144. This hoisting device comprises a driving motor, a brake means mounted on one side of the driving motor for imparting a braking force to a rotating shaft of the driving motor, and a speed reducer mounted on the other side of the driving motor for reducing the rotational speed of the driving motor to output to a sheave.
The elevator hoisting device of this type, however, suffers from a problem that the axial length of the device is large since the brake means, driving motor and speed reducer are arranged linearly or in series in an axial direction.
The present invention was made in view of the above problem and an object thereof is to provide a thin hoisting device for an elevator, the axial length of which is small.
To achieve the above-noted object, the present invention provides an arrangement for an elevator hoisting device, in which a driving motor is made cylindrical, and a brake system is accommodated radially inwardly of the driving motor.
A hoisting device for an elevator according to a preferred embodiment includes a cylindrical driving motor, a brake system accommodated radially inwardly of the driving motor for applying a braking force relative to a rotary portion of the driving motor and a speed reducer, disposed on one side of the driving motor and the brake system in a tightly contacting manner, for reducing and outputting the rotational speed of the motor to a sheave.
In this invention, since the driving motor is made cylindrical and the brake system is accommodated radially inwardly of the driving motor, the driving motor and the brake means overlap in the radial direction. This make the axial length of the hoisting device short by a length corresponding to the axial length of the brake system. Accordingly, the hoisting device can be thinned to that extent.
It is preferable that the brake system is formed into a cylindrical shape, and a detector for detecting rotational speed of the sheave is disposed radially inwardly of the brake system. This can prevent the axial length of the hoisting device from being increased even if a detector is additionally mounted.
It is also preferable that the brake system includes: an annular stationary member, a shoe radially movably supported on the stationary member, and a press portion for imparting a radially outward biasing force to the shoe, and the shoe is adapted to be pressed against an inner circumferential surface of the rotary portion of said driving motor. In a case where a shoe is constructed so as to be pressed against an inner circumferential surface of the rotary portion of the driving motor, the rotary portion of driving motor and a brake drum can be shared. Accordingly, the hoisting device can be made simple in construction and compact in size.
In a case where the internal gear of the reduction gear and the sheave are made integral with each other, the attachment of the sheave to the internal gear is no more needed, and the construction can be simplified.
In a case where seal members are provided between the input shaft and the carrier and between the carrier and the internal gear to sealingly close an interior of said speed reducer, there is no more need to dispose separate seal members between the relevant portions when the brake system and the speed reducer are assembled to the driving motor.
Moreover, in a case where a hoisting device for an elevator is constructed by a driving motor, and a brake system having therein two brake operating portions, the brake force is doubled to thereby improve the safety, and since two brake operating portions are provided in a single brake device, the hoisting device can be miniaturized.
The present disclosure relates to the subject matter contained in Japanese patent application No. Hei. 11-188538 (filed on Jul. 2, 1999) and 2000-102725 (filed on Apr. 4, 2000), which are expressly incorporated herein by reference in their entireties.